Air conditioning apparatus having condensate disposal means



Jan. 8, 1957 c. D. PIGMAN 2,776,554

AIR CONDITIONING APPARATUS HAVING CONDENSATE DISPOSAL MEANS Filed Oct. 21, 1954 2 Sheets-Sheet l FIG.|

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{ 25 INVENTOR.

C ALVIN D. PIGMAN HIS ATTORNEY C. D. PIGMAN Jan. 8, 1957 AIR CONDITIONING APPARATUS HAVING CONDENSATE DISPOSAL MEANS 2 Sheets-Sheet 2 Filed Oct. 21. 4954 FIG. 3

INVENTOR. CALVIN D. PIGMAN HIS ATTORNEY United States Patent AIR CONDITIONING APPARATUS HAVING CONDENSATE DISPOSAL MEANS Calvin D. Pigman, Lyndon, Ky., assignor to General Electric Company, a corporation of New York Application October 21, 1954, Serial No. 463,794

Claims. (Cl. 62-140) My invention relates to self-contained air conditioning units and more particularly to the means incorporated in such units for handling the moisture condensed from the indoor air.

During the operation of a self-contained air conditioning unit a portion of the atmospheric moisture or water vapor contained in the indoor air condenses on the evaporator surfaces of the unit. Over a period of time a considerable quantity of water accumulates and must be removed. In most units the water or condensate is disposed of by being sprayed in a fine mist upon the condenser surfaces of the unit, where it is then reevaporated by the outdoor air. This method is used since in addition to disposing of the condensate it increases the capacity of the condenser and thus the capacity of the unit itself.

Obviously, in this preferred way of handling the condensate some means must be. provided for getting the condensate from the evaporator to the condenser surfaces in a fine spray. The customary manner of doing it has been to introduce the condensate into the stream of outdoor air flowing over the condenser. But the fan or blower arrangement for setting up the evaporator and condenser air streams varies considerably from the one type of conditioning unit to the next; and the means which are satisfactory for introducing the condensate into the condenser air stream with one fan or blower arrangement are not necessarily usable with another arrangement. For example, the slinger rings commonly used with condenser fans rotating about a horizontal axis cannot be used satisfactorily in units where the condenser fan or blower is mounted to rotate about a vertical axis. In fact, none of the devices heretofore employed for getting the condensate into the condenser air stream have been readily usable in units having vertically mounted air moving means. Either because of the noise created, the failure to take care of any condensate not completely re-evaporated on the condenser, or the poor spray distribution eflected across the condenser surfaces, these devices have not been able to handle the condensate in the most desirable manner.

Accordingly, it is an object of my invention to provide new and improved condensate handling means for use in air conditioning units having their condenser air moving means mounted for rotation about a vertical axis.

it is another object of my invention to provide an improved air conditioning unit utilizing a vertically mounted blower for creating its condenser air stream and including a novel arrangement for introducing the evaporator condensate into the condenser air stream.

A futher object of my invention is to provide a new and improved condensate lifting and spray device for introducing evaporator condensate into the condenser air stream of an air conditioning unit, which lifting and spray device is adapted to be mounted on and rotate with a vertically mounted centrifugal blower.

in carrying out my invention, 1 provide a self-contained 2,776,554 Patented Jan. 8, 1957 air conditioning unit having an evaporator, a condenser, and means for moving a stream of indoor air over the evaporator and a stream of outdoor air over the condenser. In the unit these various components are so arranged that the means for setting up the condenser air stream is mounted to rotate about a vertical axis. By my invention I incorporate in the unit improved means for handling the water vapor condensed on the evaporator, which means include a novel arrangement for introducing this evaporator condensate into the condenser air stream. In this arrangement the condensate is collected in a sump disposed beneath the condenser air moving means and is introduced into the condenser air stream by novel lifting tubes mounted on and rotating with the air moving means. These lifting tubes extend downwardly from the air moving means into the sump and upon rotation of the air moving means they lift the condensate from the sump by centrifugal action and expel it into the turbulent condenser air stream. The tubes may be so formed that the condensate is expelled into and atomized by the turbulent air stream without any droplets of water striking the air moving means itself.

The novel features which I believe to be characteristic of my invention are'set forth with particularity in the appended claims. My invention, however, both as to its U organization and method of operation may be best under- 7 my improved condensate handling means;

Fig. 2 is a vertical sectional view taken through the air conditioner of Fig. 1 and showing the condensate handling means thereof;

Fig. 3 is a plan view of the centrifugal blower included in the unit of Fig. 1 for blowing a stream of outdoor air over its condenser; and

Fig. 4 is a fragmentary elevational view in partial section showing in detail the novel means mounted on a centrifugal blower of Fig. 3- for introducing the evaporator condensate into the condenser air stream.

Referring now to Fig. 1 I have shown therein a selfcontained air conditioning unit 1 adapted to be mounted in a window of the room to be conditioned. The conditioner 1 includes a portion 2 projecting into the room and a portion 3 projecting without the room. A gasket 4 is provided intermediate the two portions to prevent leakage of outdoor air through the window into the room.

The room air to be cooled is drawn into the unit through an opening 5 extending longitudinally across the front of the indoor portion 2. After being cooled the room air is then discharged outwardly back into the room through a center grill 6 and a longitudinal opening 7 which are also disposed in the front of the unit but below the opening 5. The heat picked up within the unit from the indoor air stream passed therethrough is rejected to an outdoor air stream which is also passed through the unit. This outdoor air is drawn into the unit through a plurality of slots 8 on the sides of the outdoor portion 3 and is discharged back into the atmosphere through a plurality of slots 9 in the rear of the outdoor portion. Although in Fig. 1 the slots 8 are shown only on the one side of the outdoor portion 3, it will be understood that they are also provided on the other side of portion 3. The position of the rear slots 9 may be seen by reference to Fig. 2.

For setting up the indoor and outdoor air flows there are included in the unit 1 a pair of centrifugal blowers 10 and 11. As shown in Fig. 2 these blowers are mounted in a vertical in-line relationship. That is, they are both mounted for rotation about the vertical axis with the one blower being mounted directly above the other. A single electric motor 12 disposed between the two blowers serves as the driving means for both.

When the motor 12 is energized so as to rotate the blowers, the upper blower draws room air in through the opening 5 in the front of the unit. As shown by the arrows in the diagram, the room air stream passes from the opening 5 through a passage 13 in the upper portion of the unit into the intake 14 of the blower. The room air after passing through the blower 1b is then discharged into a chamber 15 lying behind a refrigerant evaporator 16. From the chamber 15 the room air flows over and through the evaporator 16 and is cooled thereby. Additionally, considerable moisture or water vapor is condensed from the room air by the evaporator 16. After passing over the evaporator 16 the cooled and dehumidified room air then passes outwardly into the room through the grill 6 and the opening 7.

The evaporator 16 whereby the room air is cooled and dehumid-ified is supplied with cold condensed refrigerant from a condenser 17 mounted at the rear of the unit. The evaporator 16 and the condenser 17, as shown are both of the conventional fin and tube type, and they are connected in a series flow relationship in a closed refrigeration system. The closed refrigeration system in which they are connected, is, however, not shown since it will be understood that any of the well-known refrigeration systems may be used. The system, of course, in eludes a compressor for withdrawing gaseous refrigerant from the evaporator 16 and supplying it at a higher pressure to the condenser 17, and an expansion means for expanding the liquefied refrigerant as it passes from the condenser to the evaporator.

The heat which is picked up from the room air by means of the evaporator 16 is rejected to the outside atmosphere by means of the condenser 17. As above mentioned, the slots 8 provide a means for bringing outside air into the unit 1, and upon rotation of blower 11 outside air is drawn through those slots. The outdoor air after entering the slots flows through a suitable passageway 18 defined in the unit until it reaches the inlet 19 of the blower 11. The motor 12 for driving both the blowers 10 and 11 is positioned in the passageway 18 so that it is cooled by the stream of outdoor air flowing 'therethrough. After passing through the blower 11 the outdoor air is discharged into a chamber 20 provided behind the condenser 17. From this chamber 21 the outdoor air then flows outwardly over and through the condenser 17 and through the slots 9 back into the outside atmosphere. In passing over the condenser 17 the stream of outdoor air absorbs therefrom the heat which was given up by the indoor air to the evaporator 16. In other words, the outdoor air in flowing over the condenser 17 picks up the indoor heat absorbed by evaporator 16 so that it is rejected to the outside atmosphere.

In the air conditioning unit 1 the condenser air stream in addition to carrying away the heat rejected by condenser 17 also serves as a means for disposing of the moisture or water vapor condensed on evaporator 16 during the operation of the unit. More specifically, during the operation of the unit the evaporator condensate is introduced into the condenser air stream on the upstream side of the condenser. The air stream carries the condensate to the condenser and deposits it therein. The condensate is then evaporated by the condenser heat and is carried away as water vapor by the outgoing air stream leaving the condenser. The evaporative cooling so applied to the condenser increases its capacity and thereby the capacity of the entire unit.

In accordance with my invention and as will now be explained, i have provided new and improved means in the unit 1 whereby the evaporator condensate is introduced into the condenser air stream. As shown in Fig. 2 there is positioned directly below the evaporator 16 a gutter or trough 21 for catching any condensate dripping from the evaporator. The trough 21 extends for the length of the evaporator so that all of the condensate formed on the evaporator falls into it. From the trough 21 the water or condensate flows through a tube or pipe 22 to a collecting sump 23 which is positioned beneath the condenser blower 11. In my preferred embodiment, the sump 23 is formed by a depression or recess 24 in the base member 25 of the unit housing. However, it will be understood that a pan or receptacle separate from the base member could be used as the sump.

In order to introduce the condensate from the sump 23 into the condenser air stream, I have provided in the unit 1 improved condensate lifting and spray means which are particularly adapted to be mounted on and rotate with a vertically mounted centrifugal blower. As may be better seen in Figs. 3 and 4 this condensate lifting and spray means comprises a pair of tubes 26 and 27 which are mounted directly on the blower 11. The blower 11 itself comprises a generally horizontal back plate 28, a plurality of blades 29 extending vertically therefrom and an annular stiffening rim 30 attached to the periphery of the blades at their upper ends; and during the rotation of the blower the outdoor air is drawn downwardly into the space inside the blower defined by the inner edges of the blades 29 and the back plate 28, and then is discharged outwardly therefrom between the blades 29 by means of centrifugal action. The condensate lifting tubes 26 and 27 are so mounted on the blower that they discharge the condensate into the turbulent air stream leaving the blower. More specifically, the condensate lifting tubes are mounted by means of the blower back plate 28 and extend downwardly from the inside of the blower through the back plate into the condensate sump 23.

The condensate lifting tubes 26 and 27 are so constructed that upon rotation of the blower they raise the condensate from the sump 23 by means of centrifugal ac tion. Thus taking for example the tube 27, it being understood that the tube 26 is identical thereto, the tube 27 includes a lower portion 31 beneath the base plate 28, which runs more or less horizontally and at an angle to the axis of rotation of the blower. This horizontal portion 31 of the tube terminates at a point between the axis of rotation of the blowers and the periphery thereof and is somewhat curved at its extreme inner end so that the opening 32 at the end of the tube faces in the direction of travel of the blower. In my preferred embodiment the inner end of the tube and thus the opening 32 lie adjacent the axis of rotation of the blower. From the opposite or outer end of the horizontal tube portion 31 a substantially vertical portion 33 of the tube continues upwardly through the base plate 28 into the blade section of the blower. More exactly, as may be seen clearly in Fig. 3, this vertical portion 33 is so disposed that the outlet opening 34 at the upper end thereof is disposed between an adjacent pair of the blades 29. The vertical portion further has a deflector member 35 mounted at the end thereof to aid in forming the proper spray distribution as the condensate is ejected from the outlet opening 34. This deflector member, whose action will be fully explained hereinafter, extends outwardly over the opening 34 so as to partially block it.

Upon the rotation of the blower 11 the lifting and spray tubes 26 and 27 lift the water from the sump 23 and eject it int-o the condenser air stream in such a manner that a good spray distribution is obtained and also in such a manner that the blower itself is not struck with droplets of water so as to create noise. Since the opening 32 at the lower end of the tube faces in the direction of travel of the blower, upon the rotation of the blower the inertia of the condensate in the sump causes it to enter the moving open end of the tube with a velocity depending upon the radial position of opening 32 relative to the axis of rotation of the blower. Once the water enters the tube, centrifugal force created in the generally horizontal portion 31 causes the water to flow outwardly toward the periphery of the blower.

By properly shaping the tube, an additional force may also be utilized to aid the centrifugal force. This additional force arises as the condensate moves outward in the tube portion 31 to points of increased peripheral velocity. As the water moves from one point on the tube to a second point of higher peripheral velocity, it must either be forcibly restrained by the tube or else by the time it reaches the second point it must move backward with respect to a radius through the first point. The backward movement or tendency to move backward is, of course, due to its lesser peripheral velocity as it leaves the first point. If the tube is slanted backward from its inner end out, a radial component of force is developed as the tube attempts to restrain the water from relative rotation with respect to the blower wheel, and this force aids the centrifugal force in carrying the water along the tube.

The slope or slant of the tube which gives the maximum effect is somewhat between a straight radial path and the path which an unrestrained particle would follow in moving outward on the back plate of the blower wheel. Conversely, a tube slanted forward from the center out would develop a force to oppose the centn'fugal force. Thus it will be seen that the velocity of flow of the water can be regulated by varying the slope or slant of the horizontal tube portion 31. Since to prevent clogging the tube is made larger in cross section than necessary for the expected flow, any increased resistance to flow resulting from the greater length of a slanted tube is negligible.

When the condensate reaches the end of the horizontal portion 31 its momentum causes it to travel up the vertical portion 33 of the tube until it reaches the outlet 34. From the outlet 34 the water is then ejected outwardly into the condenser air stream. The crosssection of the tube throughout its entire length both vertical and horizontal is, of course, of such a size that any small dirt particles contained in condensate will not cause clogging.

Since the condensate is moving vertically upward as it nears the discharge opening 34, it thus has a vertical component of movement as well as a tangential component as it leaves the tube. Through the use of a properly shaped deflecting means, as for example the deflector 35, the vertical component of movement of the condensate may be so controlled as to obtain the most advantageous spray distribution into the air stream. The deflector 35, for example, so guides the condensate leaving the tube that it not only flies outwardly between the adjacent blades on the opposite sides of the tube but also sprays somewhat upwardly from the horizontal. This causes the water to be introduced into the very top of the air stream leaving the blower. Thus as the con densate begins to fall due to gravity, it falls through the entire air stream leaving the blower and as a result there is a better chance that all the condensate will be atomized by the air stream. Further, the entire air stream from top to bottom will include some moisture so that all the air striking the condenser contains some moisture. In this manner an eflicient distribution of moisture across the entire condenser is effected.

As mentioned above, the outlet 34 of the tube 27 and the similar outlet of the tube 26 are positioned between adjacent pairs of the blades 29. It has been found that by this positioning of the outlet ends of the tubes, very desirable results are secured. By so positioning the ends of the tubes and particularly if deflector means are used therewith, the water ejected from the tubes can be caused to pass upwardly into the condenser air stream without striking the blower at all. In other words, the condensate flies into the condenser air stream without any droplets thereof hitting the blades or other resonating surfaces. This greatly reduces the noise level of the unit since when the resonating blower surfaces are struck by condensate, a cracking or popping noise is often created. Further, by positioning the outlets of the tubes between adjacent blades the condensate discharged therefrom is ejected into the most turbulent portion of the condenser air stream. That is, it is ejected into the swirling eddying air just as it leaves the surfaces of the blades 29. This is advantageous in that the turbulent action of the air thereby aids greatly in causing the condensate to be vaporized or atomized. The better the condensate is vaporized and spread throughout the entire condenser air stream, the better of course is the spray distribution across the condenser; and the better the spray distribution across the condenser the more efiicient is its operation. To further aid in the vaporization of the condensate, the outlets of the tubes may be shaped so as to provide a fine spray. For example, in the preferred embodiment illustrated, the deflector 35 causes such a fine spray to be created.

It will also be noted that in the unit 1 any condensate which is not vaporized by the condenser air stream or not re-evaporated by the condenser after being deposited thereon is returned to the sump 23. Any condensate not vaporized by the condenser air stream or dripping from the condenser 17 merely falls onto the bottom plate 25 of the unit and flows along it back to the sump 23. Thus there is never any undesirable dripping of the condensate from the unit.

While in accordance with the patent statutes, I have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a self-contained unit for conditioning a room, an evaporator, means for blowing a stream of room air over said evaporator to cool said air and condense water vapor therefrom, a sump for collecting the water condensed on said evaporator, a condenser, a centrifugal blower having vertical blades, means rotatable about the Vertical aixs for blowing a stream of outdoor air over condenser, said blower means being positioned above at least a portion of said sump, and at least one lifting tube mounted on said blower means for introducing the condensate water from said sump into said stream of outside air upstream from said condenser, said lifting tube extending downwardly from the inside of said blower means into said sump with the lower end of said tube being spaced inwardly from the air moving blades of said blower means and the upper end of said tube being within said blower and adjacent said blades, whereby upon the rotation of said blower means said tube lifts said condensate water from said sump by centrifugal action and expels said water into the stream of outside air flowing through said blower means.

2. In a self-contained unit for conditioning a room, an evaporator, means for blowing a stream of room air over said evaporator to cool said air and condense water vapor therefrom, a sump for collecting the water condensed on said evaporator, a condenser, a centrifugal blower rotatable about a vertical axis for blowing a stream of outdoor air over said condenser, said blower having a generally horizontal back plate and a plurality of blades projecting vertically upward therefrom, said back plate overlying at least a portion of said sump, and at least one lifting tube mounted on said blower for introducing the condensate water from said sump into said stream of outdoor air upstream from said condenser, said lifting tube extending downwardly from the inside of said blower through said back plate into said sump with the lower end of said tube being spaced inwardly from said blades of said blower and the upper end of said tube being within said blower and adjacent said blades, whereby upon the rotation of said blower said lifting tube lifts said Condensate from said sump by centrifugal action and expels said water into the stream of outdoor air flowing through said blower.

3. In a self-contained unit for conditioning a room, an evaporator, means for blowing a stream of room air over said evaporator to cool said air and condense water vapor therefrom, a sump for collecting the water condensed on said evaporator, a condenser, a centrifugal blower rotatable about a vertical axis for blowing a stream of outdoor air over said condenser, said blower having a plurality of vertically extending blades and overlying at least a portion of said sump, and at least one lifting tube mounted on said blower for introducing the condensate water from said sump into said stream of outside air upstream from said condenser, said tube extending downwardly from the inside of said blower into said sump and being adapted to lift said water from said sump by centrifugal action upon the rotation of said blower, and the outlet of said tube being within said blower and disposed between an adjacent pair of said blades to eject said water outwardly 20 therebetwee'n into the turbulent air stream leaving said blower, whereby said water is atomized and carried away by said air stream without any droplets thereof striking said blades of said blower.

4. The apparatus of claim 3 including deflector means at the outlet of said tube for causing'said Water to be ejected as a fine spray.

5. The apparatus of claim 3 in which the portion of said tube adjacent said outlet extends upwardly from the horizontal to cause the water discharged from said tube to flly upwardly as well as outwardly into said air stream.

References Cited in the file of this patent UNITED STATES PATENTS 2,115,294 Woodrufi Apr. 26, 1938 2,509,031 Bockmeyer May 23, 1950 2,515,262 Powers July 18, 1950 2,667,765 Harris Feb. 2, 1954 

